Overshot



Ogtfzs. 194eE N. T. BREAUX.

OVERSHOT Filed Aug. 20, A1945 3 sheets-sheet 1 FT'BQ.

Patented Oct. 29, 1946 UNITEDv STATES PATEN T oFFlcE ovERsHo'r Neil T. Breaux, Houston, Tex.

Application August 20, 1945, Serial No. 611,487

' s claims. (o1. 294-86),

This invention relates to an overshot type of pipe puller. Y

'An' object of the invention is to provide a tool of the character described which may be lowered into a well bore and telescoped over a pipe in the bore and engaged with an external coupling of the pipe whereby the pipe may be pulled from the well bore.

In one embodiment of the invention the overshot is of such construction that it may be engaged with a beveled type of coupling or withv the upset portion of the pipe.

Another object of the invention is to provide an overshot which may be readily released from the pipe and withdrawn in case the pipe cannot be pulled. l

With the above and other objects in view the invention has particular relation to certain novely features of construction, operation and arrange-2 ment of parts, examples of which are given in this specification and illustrated in the accom-v panying drawings, wherein:

Figure 1 is a vertical, sectional view ofthe tool .I

as being lowered over the stuck pipe.

Figure 2 is a vertical, sectional view thereof Y showing the coupling-engaging dogs retracted and passing over the coupling. Figure 3 is a vertical, sectional view showing the dogs in engagement underneath the coupling. s

ment with a beveled coupling or `upset end of af pipe section.

Referring now more particularly to the draw-l ings wherein like numerals of reference designate similar parts in each of the figures, the numeral I designates the'tubular body of the tool whose lower end is internally thickened forming thev infside, annular, upwardlyl facing shoulder 2. AThe lower end of the body is also downwardly'and inwardly tapered as shown. Screwed into the upper end of the body there is a coupling 3 which l lower end of the tubular'operisl connected to the atingstring 4.

VWithin the body I there is the tubular actuator. 5 whose lower end has ythe vertical bores 6 and enclosing the coil springskl. There are Vthe sup/ porting legs 8 whose lower ends are seated on the shoulder 2 and whose upper ends support the coil springs 'I whereby the actuator 5 is yieldingly supported. Y

The actuator] 5 has a side slot,v or keyway 9 cut therein and a key IIJ is ancho-red to the body 'I and-its inner end projects into :the keyway. The keyway` 9 is `of limited lengths@ as to limit the range of vertical movement of the actuator 5. f

This actuator has the spaced slots VI.Ik cut in its 'upper end and between said slots said upper end has the upwardly and `outwardly tapered faces I2 which are providedwith the arcuated grooves I3 nearl their-lower margins,v as more accurately shown in Figures 1, 2 and 6.

Within the body I above the-dog actuator 5 there is Vthe tubular carrier I4 and interposed between the Aupper end ofl this carrier and the lower end of., the coupling 3 there is a coil f way I6.

The carrier I4 has an external longitudinal keyway rIii therein leading downwardly from the upper endV thereof and a key I I is anchored to the body with its inner end projecting into the key- The lower end of the carrier I4 has the vertical slots I8 spaced apart therearound, as more accurately shown in Figures 1, 2 and 5, and' pivotally mounted in these slots are the coupling-engaging dogs I9 whose upper ends are pivoted on the transverse pins 2G which are mounted in the carrier. The extreme lower ends of the dogs v.are formed with the depending arcuate ribs 2| which seat in the corresponding grooves I3 when the dogs are in engaged positionand above said ribs the dogs are formed with the inwardly extended projections 22 provided to engage under the coupling 23 of the stuck pipe 24, as more accurately shown in Figure 3.

ered into the .Well bore over the pipe 24 to be pulled. While being lowered theactuator 5 will be held in its upper position by the springs 'I and the carrier `III will be held in' lower position by the spring I5 with the projections 2| ofthe dogs I9 seated in the grooves I 3. The projections 22 of said dogs will thus be held in their inner position. When the lowerends of the dogs'strike the upper end of the collar 23A said dogs will be.

moved outwardly and upwardly along the upwardly flared,V faces I 2, as shown in Figure 2, thus placing the spring' I 5 under compression.v When the projections 22 of saiddogs pass the lower end of the coupling 23lthey will be v'free to move in- The tool may be assembled `as shown and low-` wardly and they will be forced inwardly by the tapering faces l2 being forced inwardly by the pressure of the .spring l5, as illustrated in Figure 3. An upward pull may now be exerted on the tool through the operating string 4 and as the tool moves upwardly the springs 'l will be compressed until the inside shoulder 2 engages the lower end of the actuator 5. The dogs will thus be locked in engaged position and an upward pull may be taken on the operating string 4 and the pipe 24 may thus be withdrawn from the well` In some cases the sections of pipe may be coupled together by means of a, pipe coupling as 23a which is beveled at its ends. In such case the shape of the dogs l9a is Somewhat different from the shape of the dogs i9, the difference being that the inward projections 22a do not have an abrupt upwardly facing shoulder but these projections are tapered to conform to the taper of the coupling, all as shown in Figure 8. This embodiment of the tool, as shown in Figure 8, may also be used for pulling up-set pipe, that is pipe the abutting ends of whose sections, are bell shaped.

If the engaged pipe is so tightly stuck that it cannot be withdrawn it is desirable to release the overshot. This may be done by maintaining tension on the operating string so as to hold the key l'l disengaged from the keyway I6, as shown in Figure 3, and turning the overshot either to the left or right until the dogs I9, or Illa. as the ease may be. register with the slots Il and thereupon they will move outwardly in said slots into the position shown in Figure 4 and will clear the coupling, or external enlargement, of the pipe so that the tool may be withdrawn from thewell.

What I claim is:

1. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly mounted in the body but keyed against rotation therein, a tubular carrier in the body, a yieldable seat above the carrier in the body against which the carrier is seated, dogs pivoted to and depending from the carrier, said actuator and dogs having co-operating parts effective to move the dogs inwardly into engagement underneath an external projection on the pipe upon downward movement of the carrier relative to the actuator.

2. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly supported in the body, but keyed against rotation therein, a tubular carrier in the body above the actuator, dogs pivoted to and depending from the carrier and adapted to be moved outwardly by an external projection on the pipe as the overshot is moved downwardly over said projection, yieldable means acting against the carrier, said actuator and dogs having co-operating parts effective to place said yieldable means undercompression as said dogs move outwardly and to force said dogs inwardly, by said yieldable means, when the dogs have passed beneath said projection to cause the dogs to engage underneath said projection.

3. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly mounted in the body but keyed against rotation therein, a tubular carrier in the body, means, releasable upon upward movement of the body relative to the carrier, for preventing the rotation of the carrier relative to the body, a yieldable seat above the carrier in the body against which the carrier is seated, dogs pivoted to and depending from the carrier, said actuator and dogs having co-operating parts effective to move the clogs inwardly into engagement underneath an external projection on the pipe upon downward movement of the carrier relative to the actuator, said actuator having slots to receive the dogs to permit their release from the projection upon release of said means and rotation of the body.

4. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly supported in the body, but keyed against rotation therein, a tubular carrier in the body above the actuator and keyed to, but releasable from, the body, dogs pivoted to and depending from the carrier and adapted to be moved outwardly by an external projection on the pipe as the overshot is moved downwardly over said projection, yieldable means acting against the carrier, said actuator and dogs having co-operating parts effective to place said yieldable means under compression as said dogs move outwardly and to force said dogs inwardly, by the action of said yieldable means, when the dogs have passed beneath said projection to cause the dogs to engage underneathl said projection, said actuator having upper end slots to receive said dogs upon said release of the carrier and rotation of the body to release the dogs from said projection.

5. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly mounted in the body but keyed against rotation therein, a tubular carrier in the body above the actuator, means, releasable upon upward movement of the body relative to the carrier, for preventing the rotation of the carrier relative to the body, a yieldable seat above the carrier in the body against which the carrier is seated, dogs pivoted to and depending from the carrier and adapted to engage underneath an external projection on the pipe, said actuator and dogs having co-operating parts eiective to move the dogs inwardly upon downward movement of the carrier relative to the actuator, said actuator having recesses to receive the dogs to permit their release from the projection upon release of said means and rotation of the body.

6. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly supported in the body, but keyed against rotation therein, a tubular carrier in the body above the actuator and keyed to, but releasable from, the body, dogs pivoted to and depending from the carrier and adapted to be moved outwardly by an external projection on the pipe as the overshot is moved downwardly over said projection, yieldable means acting against the carrier, said actuator and dogs having cooperating parts eiiective toplace said yieldable means under compression as said dogs move outwardly and to force said dogs inwardly, by the action of said yieldable means, when the dogs have passed beneath said projection to cause the dogs to engage underneath said projection, said actuator having recesses to receive said dogs upon said release of the carrier and rotation of the body, to release the dogs from said projection.

'7. An overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly mounted in the body but keyed against rotation therein, a tubular carrier in the body above the actuator, means, releasable upon upward movement of the body relative to the carrier, for preventing the rotation of the carrier relative to the body, a yieldable seat above the carrier in the body against which the carrier is seated, pipe engaging means depending from the carrier and adapted to engage underneath an external projection on the pipe, said actuator l and pipe engaging means having (so-operating parts eiective to move the pipe engaging means inwardly upon downward movement of the carrier relative to the actuator, said actuator being recessed to receive the pipe engaging means to permit release thereof from the projection upon release of said carrier and rotation of the body.

8. A11 overshot comprising, a tubular body adapted to telescope over a pipe in a well, an actuator yieldingly supported in the body, but keyed against rotation therein, a, tubular carrier in the body above the actuator and keyed to, but releasable from, the body, pipe engaging means pivoted to and depending from the carrier and adapted to be moved outwardly by an external projection on the pipe as the overshot is moved downwardly over said projection, yieidable means acting against the carrier, said actuator and pipe engaging means having co-operating parts effective to place said yieldable means under compression as said pipe engaging means moves outwardly and to force said pipe engaging means inwardly, by the action of said yieldable means, when the pipe engaging means have passed beneath said projection to cause the pipe engaging means to engage underneath said projection, said actuator being recessed to receive said pipe engaging means upon said release of the carrier and rotation of the body, to release the pipe engaging means from said projection. 

